This invention relates to a noise filter, particularly suited for power supply line filtering and the like. The invention also relates to a terminal structure especially suited for use in such a noise filter and the like.
An electrical device, such as a noise filter is usually constructed so that metallic terminals are fixed to a case of synthetic resin, and inner electrical wires are connected to the metallic terminals by a soldering operation. In recent years, there has been great demand for automatic manufacturing, particularly requiring the automated connection of the metallic terminals to the interior wires. However, the connection between conventional metallic terminals and the wires has been difficult to automate, since holes or grooves are used for inserting the wire. Sometimes it is necessary to provide a manual insertion of a wire into the wire connection part in a metallic terminal, and further the wire should be held manually until the soldering operation is completed so that the wire is not removed from the terminal.
The present invention has as one of its objects a terminal structure that eliminates the above-mentioned disadvantages and as being suitable for the automated feeding and holding and soldering of a wire to the metallic terminal.
A major object of the present invention is a noise filter that reduces manufacturing cost and improves mass production. These objects are achieved through use of a noise filter provided by an insulator case composed of a case main body and a cap that include interfitting elements which resiliently engage each other to maintain the case main body and cap fitted together. The case main body includes coil fixing projections and capacitor position restricting ribs, as well as a number of metallic terminals that provide electrical connections to the electrical components within the insulator case. Portions of the metallic terminals extend outside the insulator case and are firmly held between adjacent edges of the case main body and cap. These terminals advantageously are each provided with a U-shaped bent portion which fits into a concave part in the case main body. Each metallic terminal includes a connection part within the case main body that extends substantially vertically, with the upper end of this connection part including opposed hook-shaped projections that are adapted to hold a wire therebetween. These hook-shaped connection parts are preferably all positioned at the same level within the case main body, to facilitate an automated soldering operation.
The invention will be more completely understood by reference to the following detailed description.